A great number of resilient valves are disclosed throughout the patent literature and are found in the marketplace in everything from sports bottles, spigots for water and wine vessels, and various dispensers in the food and beverage industry, to many medical devices. A resilient valve member refers to a movable member present within a valve assembly that can temporarily seal an orifice in liquid dispensing or liquid/gas pressure relief. Ideally, resilient valve members are molded from a unitary piece of rubber or other defolinable, stretchable material such as a silicone elastomer. A resilient valve member is then seated into the valve assembly so that it can bias against and seal an orifice opening, usually through a bias against a valve seat. Holding the resilient valve member into the valve assembly may be accomplished by a simple press/friction fit of the valve member into a complementary shape, or by a separate retaining ring used to lock the member firmly down. Pressure applied to the opposite side of the seal, either from the insertion of a straw tube (mechanical pressure), or from impinging liquid or gas (liquid/gas pressure, such as seen in check-valves) pushes the resilient member off the seal and opens the package for liquid or gas exit. Removal of the tube, or cessation of the liquid/gas pressure, causes the resilient valve to return to its original biased position, sealing the opening. The return of the valve member is possible through the “memory” inherent the resilient valve member. That is, rubber and various silicone elastomer parts have the ability to return to their molded shapes after being temporarily deformed such as stretching. Hence these materials are ideal for use in molding resilient valve members.
Resilient valve members may be classified as plug valves when the actual sealing portion of the resilient member is plug shaped in order to seal (or plug) against a circular opening like a small orifice. In particular, a small tubular member may extent from a closure into the inside of a liquid package, and may terminate in the shape of a valve seat (a chamfered circumferential lip). The plug portion of the resilient valve member can be proportioned and shaped such that it will fit partly within the end of the tube, sealing against the valve seat. Stretchable or otherwise deformable extensions emanating from the plug portion of the resilient valve member allow the plug portion to be temporarily pushed off the seat by an inserted spigot or by impinging pressure through the stretching or deforming of the extensions. The more relevant art in this refined area of resilient plug valve members is discussed below.
U.S. Pat. No. 7,721,763 (Choksi) discloses a one-way flow valve that incorporates one of several resilient valve member designs. One configuration ('763, FIG. 3) is a relatively flat member having a disc shaped plug area and spiral flexible arms radiating from the disc area to a retaining washer-shaped periphery. Another configuration ('763, FIG. 7) is a “hat” shape with a centrally located disc plug set above a retaining washer, with the plug connected to the retaining washer with stretchable connecting arm portions. Similar configurations for the valve member are disclosed by Choksi in U.S. Pat. No. 5,727,594, particularly in FIGS. 6-8.
U.S. Pat. No. 7,287,545 (Zelson) discloses a check valve that incorporates one of a variety of resilient member designs referred to as “the molded elastomeric valve body.” As best seen in FIGS. 1 and 9 of '545, these elastomeric parts generally have a disc or plug-shaped central feature 14 connected to a relatively flat flange feature 20 (referred to as a gasket system) through any number of flexible arms 12. The resilient members are generally planar, with the gasket flange clamped around its circumference to the valve assembly by a clamping system that ensures the plug of the resilient member is biased against the valve seat.
U.S. Pat. No. 6,409,707 (Guala) discloses an anti-siphon valve for medical infusion lines that comprises a resilient member referred to as the “elastic open-close element.” Here, the element is cup-shaped when not deformed, and it comprises a circular bottom wall and skirt. The cup-shaped resilient element is clamped within the valve assembly such that the peripheral edge (the shoulder where the disc shaped top meets the circumferential skirt) is held in fluid-tight contact against the annular valve seat.
U.S. Pat. No. 6,390,130 (Guala) discloses another valve for medical infusion lines that comprises a relatively flat resilient valve member (referred to as a “diaphragm”) that comprises an annular peripheral section and a central sealing disc that are connected by a crown of spaced apart arms. The Guala diaphragm is inserted, and secured, between first and second tubular connectors such that the disc portion of the diaphragm acts on the annular valve seat to keep the valve in a normally closed state.
U.S. Pat. No. 4,712,583 (Pelmulder wt al.) discloses a passive flat-top valve for infusion systems comprising a resilient member with a valve disk that is the sealing element and a static seal ring that acts as the seal between upper and lower housing elements and as a rigid support structure from which the valve disk may be suspended. The valve disk portion of the resilient member is biased against one of the housing members to seal across an orifice.
PCT Application Publications WO 2010/055309 and WO 2010/055314 (Xianzhi et al.) disclose a dispensing valve having a resilient valve member similar in shape to the hat-shaped valve disclosed by Choski ('763). The Xianzhi valve has a central sealing valve member connected to a valve plate via a number of “biasing elements.” The valve plate is positioned lower and centrally outward from the valve member. The biasing elements are essentially stretchable straps that can stretch when the plug element is vertically displaced off its valve seat. The washer-shaped valve plate has locating holes that line up with locating posts protruding from the underside of the cap. The resilient valve is locked into position within the closure by a rigid fixing plate that sandwiches the resilient valve against the underside of the cap.
Lastly, Bargo discloses in U.S. Patent Application Publication No. U.S. 2007/0023458 a siphon head that incorporates any one of a number of elastomeric closure elements. Most of the closure elements disclosed feature a half sphere-shaped or conical head for plugging a valve seat, with the plug element connected to an outer ring through any number of elastic memory members such as arms or ribs.
Accordingly, and in spite of the variety of resilient valves seen in the prior art, it is desirable to invent new ways to configure movable valve members for use in valve assemblies/closures on liquid packaging, which may be easier and/or less expensive to manufacture. It is also desirable to find new shapes and configurations for valve members that may be easier to secure within a valve housing assembly and easier to seat against a valve seat or other orifice. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.